Maintaining fuel ions hotter than electrons would greatly facilitate controlled nuclear fusion. The parameter range for achieving this temperature disparity is shown here to be enhanced by catalyzing the α-channeling effect (wave-induced simultaneous expulsion and cooling of α particles) through minority-ion heating. Specifically, a wave can extract energy from hot α particles and transfer it to colder minority ions, which act as a catalyst, eventually forwarding the energy to still colder fuel ions through collisions. In comparison with the traditional α-channeling mechanism, the requirements are thereby relaxed on the waves that accomplish the α channeling, which no longer have to interact simultaneously with α particles and fuel ions. Numerical simulations illustrate how the new scheme may increase, for example, the effective fusion reactivity of mirror-confined plasmas.
© 2011 American Physical Society